Question about frame dragging

  • #1

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Moderator's note: offshoot from https://www.physicsforums.com/threads/what-is-frame-dragging.762986/

I am trying to understand time travel and i can understand Tipler Cylinders and the cosmic string theory that assist the possibility of time travel but I was looking at Frame dragging because that’s how CTC (closed time like curves) work but those equations have not been taught to me yet. If you could make sense of them to me in a simple and basic way so that a year seven student could understand that would be a great help.
Thankyou
TheDoctor6000
 
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Answers and Replies

  • #2
stefan r
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... those equations have not been taught to me yet. If you could make sense of them to me in a simple and basic way so that a year seven student could understand that would be a great help.
...
Most 7 year olds have not had algebra. Makes equations difficult to explain.

Pick an equation and list which parts you do understand. It is often easy to add missing information. Someone can also correct an error if there is one.
 
  • #3
I will go with th weak fram dragging équation The things I don’t understand are,
What does the w mean
Am I dividing that answer to the w by top and bottom?
And what do those letters mean I know what the numbers are on the bottom of the fraction line (they are indices) but on the top I am confused.

It would be a great help if you could answer these
And sorry if my questions are tedious to answer. I am just very interested in the possibilities of time travel and how it works.
Thankyou
TheDoctor6000
 
  • #4
stefan r
Science Advisor
Gold Member
817
232
...
Am I dividing that answer to the w by top and bottom?
And what do those letters mean I know what the numbers are on the bottom of the fraction line (they are indices) but on the top I am confused.
ω is the frame-drag rate in rad/s
ω is greek letter "omega". It is radians per second which equals 9.55 rpm. A lot of cars have a gauge that reads thousands of rpm. Multiply that number by around 100.

J is the angular momentum. I think it is the same as L if you disregard particle spin. Alina Zagitova does a beautiful demonstration of angular momentum in this video. at end of 2:57 she kicks and then pulls her arms and legs in to her center in 2:58. In 2:59 she has arms out and leg fully extended for the landing and then hops and pulls everything in for the rotations in 3:00. They have a slow motion freeze frame image at 6:04. At 4:18 she is adds angular momentum by kicking in a diagonal camel spin. She then does a sit spin(4:22) and an I-spin(4:26) using that angular momentum. She gets a full 6 seconds of spin and chews up the ice because most of her mass is directly above the skate when her foot is above her head.
If you understand and can talk about figure skating you probably understand angular momentum good enough for any casual conversation or for science fiction writing. I do not have any experience traveling through time. My impression was that a person would already become molecular soup if they get close enough to a black hole for the difference to matter. If you hand wave spaghettification then you can hand wave the spin too. Just assume classical mechanics in science fiction unless it is convenient to do otherwise.

G is the gravitational constant.
 
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  • #5
Thank you so much I appreciate all your help but what about Tipler Cylinders even if theoretical they could still aid in the possibility of time travel?
:smile:
 

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